ACEBUTOLOL HYDROCHLORIDE (a-se-byoo-toe'lole)
Monitan , Sectral Classifications: beta-adrenergic antagonist; antihypertensive; antiarrhythmic, class ii agent; Therapeutic: antihypertensive; antiarrythmic, class ii Prototype: Propranolol Pregnancy Category: B
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Availability
200 mg, 400 mg capsules
Action
Beta1-selective adrenergic blocking agent with mild sympathomimetic activity (partial beta-agonist activity). Produces negative
chronotropic and inotropic activity (i.e., decreases exercise-induced heart rate, inhibits reflex orthostatic tachycardia,
and decreases cardiac output at rest and during exercise).
Therapeutic Effect
Decreases both systolic and diastolic BP at rest and during exercise. Exhibits antiarrhythmic activity (class II antiarrhythmic
agent).
Uses
Treatment of mild to moderate hypertension. Management of recurrent stable ventricular arrhythmias.
Unlabeled Uses
Supraventricular arrhythmias, chronic stable angina pectoris.
Contraindications
Overt CHF, second- or third-degree AV block, severe bradycardia, cardiogenic shock; acute bronchospasm, pulmonary edema;
lactation; children <12 y.
Cautious Use
Impaired cardiac function, well-compensated CHF, mesenteric or peripheral vascular disease; cerebrovascular disease; patients
undergoing major surgery involving general anesthesia; renal or hepatic impairment; labile diabetes mellitus; hyperthyroidism;
bronchospastic disease (asthma, emphysema); avoid abrupt withdrawal; pregnancy (category B).
Route & Dosage
Hypertension Adult: PO 400800 mg/d in 12 divided doses (max: 1200 mg/d) Geriatric: PO 200400 mg/d (max: 800 mg/d)
Ventricular Arrhythmias Adult: PO 200 mg b.i.d. increased to 6001200 mg/d
Angina Pectoris Adult: PO 300400 mg t.i.d.
Renal Impairment Clcr <50 mL/min: reduce dose by 50%; <25 mL/min: reduce dose by 75%
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Administration
Oral
- Check apical pulse before administration. If <60 bpm or other ordered parameter, consult physician.
- Discontinue gradually over a period of 2 wk.
- Store at 15°30° C (59°86° F).
Adverse Effects (≥1%)
Body as a Whole: Fatigue. CNS: Dizziness,
insomnia, drowsiness, confusion, fainting.
CV: Bradycardia, hypotension, CHF.
GI: Nausea,
diarrhea, constipation, flatulence.
Hematologic: Agranulocytosis,
antinuclear antibodies (ANA). Metabolic: hypoglycemia (may mask symptoms of a hypoglycemic reaction).
Respiratory: Bronchospasm,
pulmonary edema, dyspnea.
Urogenital: Decreased libido; impotence.
Diagnostic Test Interference
False-negative test results possible (see propranolol).
Interactions
Drug: Other
hypotensive agents,
diuretics increase hypotensive effect; with
albuterol, metaproterenol, terbutaline, or
pirbuterol, there is mutual antagonism with acebutolol;
nsaids blunt hypotensive effect; decreases hypoglycemic effect of
glyburide; increases bradycardia and sinus arrest with
amiodarone.
Pharmacokinetics
Absorption: Well absorbed after PO administration; undergoes extensive first-pass metabolism in liver with an average bioavailability
of 40%. (In geriatric patients, bioavailability increases twofold.)
Peak: 3 h.
Distribution: Minimally into CSF; crosses placenta; is excreted in breast milk.
Metabolism: In liver to diacetolol with activity equipotent to parent compound.
Elimination: Metabolite 813 h; 5060% via bile into feces, 3040% in urine.
Half-Life: 34 h.
Nursing Implications
Assessment & Drug Effects
- Monitor BP and cardiac status throughout therapy. Observe for and report marked bradycardia or hypotension, especially when
patient is also receiving a catecholamine-depleting drug (e.g., reserpine).
- Monitor I&O ratio and pattern and report changes to physician (e.g., dysuria, nocturia, oliguria, weight change).
- Monitor for S&S of CHF, especially peripheral edema, dyspnea, activity intolerance.
- Lab tests: Monitor for drug-induced positive ANA titer during long-term therapy, especially in women and older adults; periodic
CBC with long-term therapy.
Patient & Family Education
- Know parameters for withholding drug (e.g., pulse less than 60).
- Note: Common adverse effects include insomnia, drowsiness, and confusion.
- Do not drive or engage in potentially hazardous activities until response to drug is known.
- Do not increase, decrease, omit, or discontinue drug regimen without advice from the physician. Abrupt withdrawal may worsen
angina or precipitate MI in patient with heart disease.
- Contact physician promptly at the first signs or symptoms of CHF (see Appendix F).
- Report muscle and joint pain to physician. Discontinuation of drug therapy usually reverses these adverse effects.
- Monitor for loss of glycemic control if diabetic.
- Note: Drug may mask symptoms of hypoglycemia (see Appendix F) and potentiate insulin-induced hypoglycemia in diabetics.
- Avoid use of OTC oral cold preparations and topical nasal decongestants unless approved by the physician.